To study further the role of vasoactive substances, including histamine, serotonin and kinins in antibody production and in the biologic responses to tissue and organ transplantation and to study the suitability of a variety of inhibitors of vasoactive amines and polypeptides in the suppression of antibody formation and the prolongation of allograft survival. The role of these vasoactive substances, their formation and release, on blood and lymphatic flow and on antigen transport, small lymphocyte recirculation, antigen recognition and antibody production also will be investigated as will the role of these agents in the hyperemia-permeability changes, edema, antigen-antibody complex deposition and chronic rejection of organ transplants. The effects on these changes by corticosteroids, local radiation, antilymphocyte serum and adjuvants also will be evaluated.